Radio access networks (RANs) provide for radio communication links to be arranged within the network between a plurality of user terminals. Such user terminals may be mobile and may be known as ‘mobile stations’ or ‘subscriber units.’ At least one other terminal, e.g. used in conjunction with mobile stations (MSs), may be a fixed terminal, e.g. a base station, eNodeB, repeater, and/or access point. Such a RAN typically includes a system infrastructure that generally includes a network of various fixed terminals, which are in direct radio communication with the MSs. Each of the fixed terminals operating in the RAN may have one or more transceivers which may, for example, serve MSs in a given region or area, known as a ‘cell’ or ‘site’, by radio frequency (RF) communication. The MSs that are in direct communication with a particular fixed terminal are said to be served by the fixed terminal. In one example, all radio communications to and from each MS within the RAN are made via respective serving fixed terminals. Sites of neighboring fixed terminals may be offset from one another and may be non-overlapping or partially or fully overlapping with one another.
RANs may operate according to any one of a number of available industry standard broadband protocols such as, for example, an open media alliance (OMA) push to talk (PTT) over cellular (OMA-PoC) standard, a voice over IP (VoIP) standard, or a PTT over IP (PoIP) standard. Typically, protocols such as PoC, VoIP, and PoIP are implemented over broadband RANs that may include third generation and fourth generation networks such as third generation partnership project (3GPP) Long Term Evolution (LTE) networks.
RANs may additionally or alternatively operate according to an industry standard land mobile radio (LMR) protocol such as, for example, the Project 25 (P25) standard defined by the Association of Public Safety Communications Officials International (APCO), or other radio protocols, the Terrestrial Trunked Radio (TETRA) standard defined by the European Telecommunication Standards Institute (ETSI), the Digital Private Mobile Radio (dPMR) standard also defined by the ETSI, or the Digital Mobile Radio (DMR) standard also defined by the ETSI. Because these systems generally provide lower throughput than the 3 GPP and LTE systems, they are sometimes designated narrowband RANs.
Communications in accordance with any one or more of these protocols or standards, or other protocols or standards, may take place over physical channels in accordance with one or more of a TDMA (time division multiple access), FDMA (frequency divisional multiple access), OFDMA (orthogonal frequency division multiplexing access), or CDMA (code division multiple access) protocols. Mobile stations in RANs such as those set forth above send and receive audio and/or data (e.g., encoded voice, audio, video, images, control information, text messages, instant messages, short message service (SMS), multimedia message service (MMS), e-mail, and/or audio/video streams) in accordance with the designated protocol.
OMA-PoC, in particular, enables familiar PTT and “instant on” features of traditional half duplex MSs, but uses MSs operating over modern cellular telecommunications networks. Using PoC, MSs such as mobile telephones and notebook computers can function as PTT half-duplex MSs for transmitting and receiving auditory data. Other types of PTT models and multimedia call models (MMCMs) are also available. Still further, other types of communications models for transmission and reception of other types of data are available as well.
Floor control in an OMA-PoC session, in one example, is generally maintained by a PTT server that controls communications between two or more MSs. When a user of one of the MSs keys a PTT button, a request for permission to speak in the OMA-PoC session is transmitted from the user's MS to the PTT server using, for example, a real-time transport protocol (RTP) message. If no other users are currently speaking in the PoC session, an acceptance message is transmitted back to the user's MS and the user can then speak into a microphone of the MS. Using standard compression/decompression (codec) techniques, the user's voice is digitized and transmitted using discrete auditory data packets (e.g., together which form an auditory data stream over time), such as according to RTP and internet protocols (IP), to the PTT server. The PTT server then transmits the received auditory data packets to other users of the PoC session (e.g., to other MSs in the group of MSs or talkgroup to which the user is subscribed), using for example a unicast, multicast, or broadcast communication technique.
Narrowband LMR systems, on the other hand, operate in either a conventional or trunked configuration. In either configuration, a plurality of MSs are partitioned into separate groups of MSs. In a conventional system, each MS in a group is selected to a particular frequency for communications associated with that MS's group. Thus, each group is served by one channel, and multiple groups may share the same single frequency (in which case, in some embodiments, group IDs may be present in the group data to distinguish between groups using the same shared frequency). Communications in a conventional system may take place via an infrastructure-provided repeater or repeaters, or directly via a direct mode (including talk-around) protocol.
In contrast, a trunked radio system and its MSs use a pool of traffic channels for virtually an unlimited number of groups of MSs (e.g., talkgroups). Thus, all groups are served by all channels. The trunked radio system works to take advantage of the probability that not all groups need a traffic channel for communication at the same time. When a member of a group requests a call on a control or rest channel on which all of the MSs in the system idle awaiting new call notifications, in one embodiment, a call controller assigns a separate traffic channel for the requested group call, and all group members move from the assigned control or rest channel to the assigned traffic channel for the group call. Communications then take place via the assigned traffic channel repeater. In another embodiment, when a member of a group requests a call on a control or rest channel, the call controller may convert the control or rest channel on which the MSs were idling to a traffic channel for the call, and instruct all MSs that are not participating in the new call to move to a newly assigned control or rest channel selected from the pool of available channels. With a given number of channels, a much greater number of groups can be accommodated in a trunked system as compared with conventional radio systems. In a trunked system, communications may also take place directly between MSs when operating in a talk-around mode (e.g. direct mode when infrastructure devices are also available). In some embodiments, group data transmissions may occur in a trunked radio system on an assigned trunked traffic channel, while in other embodiments, the group data transmissions may occur on an assigned data revert channel. Other possibilities exist as well.
Group communications such as group audio calls or group data transmissions may be made between wireless and/or wireline participants in accordance with either a narrowband or a broadband protocol or standard. Group members for group communications may be statically or dynamically defined. That is, in a first example, a user or administrator working on behalf of the user may indicate to the switching and/or radio network (perhaps at a radio controller, call controller, controller device, PTT server, zone controller, or mobile management entity (MME), base station controller (BSC), mobile switching center (MSC), site controller, Push-to-Talk controller, or other network device) a list of participants of a group at the time of the group communication or in advance of the group communication. The group members (e.g., MSs) could be provisioned in the network by the user or an agent, and then provided some form of group identity or identifier, for example. Then, at a future time, an originating user in a group may cause some signaling to be transmitted indicating that he or she wishes to establish a group communication session with each of the pre-designated participants in the defined group. In another example, MSs may dynamically affiliate with a group (and also disassociate with the group) perhaps based on user input or infrastructure controller device configuration or action, and the switching and/or radio network may track group membership and route new group communications according to the current group membership. In some instances, a group of MSs may be identified as a communication group, and a communication initiated to members of that communication group (whether including the synchronous or asynchronous transmission of audio or other data noted above) may be identified as a group communication session.
Communication groups may be used to communicate between groups of currently active MSs, where the groups are conventionally created (statically or dynamically) based on a type of currently active MS user or created based on a currently occurring event or incident, such as groups of currently active fire fighters, currently active police, currently active store employees, or currently active government agency employees, for responding to a currently occurring incident at a particular location.
For example, as shown in FIG. 1, an incident/response area 100 may have a defined location 102 and may have a response boundary 104 statically defined at a fixed distance 106 from the defined location 102. In other embodiments, response boundary 104 may represent a maximum transmission range of BS 130 if it were positioned at defined location 102. Various potential responders to an incident at the defined location 102 may be on scene or within the response boundary 104 at the time of the incident or shortly after the incident occurs. Each potential responder may be a person or vehicle with an associated MS (e.g., portable or vehicular MS) capable of communicating wirelessly with each other and/or with a RAN 126. Such potential responding MSs may include, for example, a pedestrian responder MS 112A (e.g., a traffic control officer operating on-foot), a motor vehicle responder MS 114A (e.g., police car), a motor vehicle responder MS 116A (e.g., fire engine), and a human-powered vehicle responder MS 118A (e.g., bicycle officer).
Each of the responder MSs may, in one example, already be actively using RF resources 128 of the RAN 126, which may be a LMR or LTE RAN providing coverage substantially throughout the incident/response area 100, illustrated in FIG. 1 as including a single fixed terminal (BS) 130 coupled to a controller device 132 (e.g., radio controller, call controller, PTT server, zone controller, MME, BSC, MSC, site controller, Push-to-Talk controller, or other network device). As illustrated in FIG. 1, using the response boundary 104 to set group membership for an incident or response required at or near the defined location 102 aids in coordinating a response to the currently occurring event or incident.
However, in addition to the current event or incident situation noted above, there may be other situations in which an initiating MS user wishes to more dynamically form a new communication group that are not possible using existing mechanisms. Accordingly, there is a need for an improved method and apparatus for dynamically forming communication groups, and more particularly, for forming communication groups based not on a current location of currently active MSs, but instead, on a location history of MSs.
Skilled artisans will appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help to improve understanding of embodiments of the present invention.
The apparatus and method components have been represented where appropriate by conventional symbols in the drawings, showing only those specific details that are pertinent to understanding the embodiments of the present invention so as not to obscure the disclosure with details that will be readily apparent to those of ordinary skill in the art having the benefit of the description herein.